1. Field of the Invention
This invention relates generally to armor systems and more specifically to features of armor structure directed to preventing certain aspects of performance degradation.
2. Background Art
Typically, high efficiency armor (composite-backed armor) that works in a non-supported, or freestanding application suffers from delamination of the composite laminate from the strike face side of the target. This delamination could occur between the composite/frontal structure interfaces, or within the composite laminate itself. This is a very common issue with laminates in high efficiency composite armor as fiber movement and inter-laminar delamination are critical to the performance of the system. Previous attempts at attaching the composite backing involved a stiff wrap or backface structure, or a mechanical through-hole attachment in attempts to control the backface deformation, which reduced the efficiency of the composite backing, or in the case of the through fasteners could create a vulnerable location in the armor system.
In typical armor applications, it is common to have a polymer spray coating on the exterior, which is applied to provide environmental protection and limit spallation of the armor. There is typically a high level of deformation that occurs on the back face of a composite backed armor after a strike with a high-energy projectile. The trauma that results from this high-energy impact may cause composite fibers to deform and break in a tensile failure, leaving a frayed, damaged surface on the backside of the armor even in situations where the threat has been defeated. In previous designs, the polymer “spall liner” coatings would “chunk” off the back and leave the armor at a high velocity upon the impact and resultant trauma that occurs when the fibers break. Polymers with properties favorable for this application (high strength, high elongation) were not able to withstand this event, primarily due to the disintegration of the fibers to which the polymer coating was bonded.